Icariin alleviates cellular injury induced by cardiac ischemia-reperfusion injury by inhibiting IRE1/JNK-induced ferroptosis

Background: Ischemia-induced cellular damage and stress responses significantly impact cellular viability and function. Icariin (ICA), known for its protective effects, has been studied to understand its role in mitigating oxygen-glucose deprivation/reperfusion (OGD/R)-induced endoplasmic reticulum (ER) stress and Ferroptosis in H9C2 cardiomyoblast cells.

Methods: We employed an in vitro OGD/R model using H9C2 cells. ICA's effects were analyzed across multiple concentrations. Key indicators of ER stress, Autophagy, and ferroptosis-including markers like Bip, PERK, IRE1, ATF6, p62, FTH1, LC3II/LC3I, and NCOA4-were assessed using Western blotting, electron microscopy, and biochemical assays. Additionally, the role of the IRE1/JNK pathway in mitochondrial dynamics and its influence on mitochondrial dynamics protein was explored through specific inhibition and activation experiments.

Results: ICA significantly reduced the activation of UPR pathways, decreased autophagic vacuole formation, and maintained cell viability in response to OGD/R and Erastin-induced Ferroptosis. These protective effects were associated with modulated autophagic processes, reduced lipid peroxidation, and decreased ferrous ion accumulation. Inhibition of the IRE1/JNK pathway and subsequent Drp1 activity demonstrated reduced mitochondrial recruitment and Mitophagy, correlating with decreased Ferroptosis markers and improved cell survival.

Conclusion: Our findings highlight ICA's potential in modulating IRE1/JNK pathway, Autophagy, providing a therapeutic avenue for mitigating Ferroptosis in myocardial ischemia-reperfusion injury (MIRI).

Autophagy; ER stress; Ferroptosis; Mitophagy; Oxygen-glucose deprivation/reperfusion; Unfolded protein response.